This invention is directed to an improved lubricant prepared from a mixture of boric acid and oil or grease or other such base medium lubricant This invention also relates to an improved selflubricating composite lubricant prepared from a mixture of boric acid and/or boric acid-forming boron oxide and various engineering polymers. More particularly, the invention relates to a mixture containing boric acid particles in a mixture and/or suspension with a particular range of particle sizes and amounts. Lubricants serve an important function in preserving machine components and extending machine operating lifetimes. Optimization of lubricant properties has remained a primary objective as machines are operated under more demanding and difficult conditions associated with increased efficiency and performance. Numerous additives have been developed, but much remains to be done to accommodate the increased demands now being made of lubricants.